A quick question regarding fitting a new stereo in a Rover 75 (X reg)

The 75 has a standard radio/cassette player at the moment without a cd
changer and I'd like to fit a Sony head unit with a 10 CD changer in the
boot. However the current stereo is completely fitted into the dash with the
front being a lot bigger than the standard sony unit.

Does anyone know if the rover stereo can easily be changed for a standard
sony one? Presumably a blanking plate would be needed to go around the
standard sony unit too.

Cheers,
Shaun.